The present invention relates to foundry practice and more in particular to a cold setting sand for foundry moulds and cores.
There is known a foundry sand which comprises a refractory filler containing magnesium and/or chromium oxides, such as chrome-magnesite or magnesite-chrome, and a binder such as alcohol-sulfite lye or water glass (A. M. Liass, "Fast Setting Foundry Sands", Mashinostroenie Publishers, Moscow, 1965).
There is also known a cold setting sand which comprises a filler, orthophosphoric acid and a powdered material containing iron oxides.
The prior art sands are disadvantageous in that they are difficult to shake out, have insufficient strength, and require heat drying. Furthermore, the powder material containing iron oxides requires pregrinding, which makes the production more complicated and expensive, and damages to cores during their removal from core-boxes and subsequent handling.